1. Field of the Invention
The present invention relates to an internal power supply circuit, a semiconductor device, and a manufacturing method of a semiconductor device, and more particularly relates to an internal power supply circuit, a semiconductor device, and a manufacturing method of a semiconductor device which are capable of optimizing a consumption current in the internal power supply circuit.
2. Description of Related Art
Semiconductor devices such as DRAMs (Dynamic Random Access Memories) are configured to operate using an internal power supply voltage obtained by raising or lowering an external power supply voltage, in addition to a voltage input from outside (the external power supply voltage). The actual value of the internal power supply voltage sometimes deviates from a design value due to manufacturing variability or the like, and thus it is adjusted at the time of manufacturing by fuse trimming or the like (see Japanese Patent Application Laid-open Nos. 2002-184178 and 2007-281139, and Japanese Patent No. 3398564).
For example, an internal power supply circuit described in Japanese Patent Application Laid-open No. 2002-184178 includes a reference-potential generating circuit that generates a reference potential and a driver circuit that supplies an internal power supply voltage based on the reference potential, where an adjustment of the reference potential is enabled by trimming a fuse included in the reference-potential generating circuit. In this manner, the level of the internal power supply voltage that varies in conjunction with the reference potential can be adjusted.
However, the current supply capability of the internal power supply voltage is not always optimal even when its level is adjusted. That is, because current supply capabilities of driver circuits are also individually different due to their manufacturing process, it is necessary to set the design value of the current supply capability larger than the minimum required value to some extent. As a result, the current supply capability of the internal power supply circuit can be excessive and generate a wasteful consumption current in the internal power supply circuit.